This invention relates generally to instrument panels for automotive vehicles of the type having a retainer panel formed with an airbag deployment opening and a separately formed deployment door installed in the opening and covered by a continuous foam and skin layer and, more particularly, to the means of controlling foam leakage past the door during manufacture of the instrument panel.
In manufacturing instrument panels of the above type, the separately formed door is typically hinged along one edge to the retainer and a gap exists along the remaining edges to provide clearance for installation and opening. The overlying foam layer is foamed in place in the space provided between the outer skin layer and an upper surface of the door and retainer members.
According to known practice, the gap between the door and retainer is masked off with adhesive tape after the door has been installed in the opening. The tape is applied to the outer surfaces of the door and retainer members across the gap and serves to block the foam material from leaking past the door. Application of such tape, although effective, adds an extra step in the manufacturing process and further presents a barrier to the direct adhesion of the foam material to the door and retainer members in the region of the masked areas.
An air bag closure assembly according to a method and construction of the invention overcomes and greatly minimizes the foregoing objections.
An instrument panel closure assembly for an air bag system of a vehicle according to the invention comprises a rigid retainer member having a top surface and a preformed air bag deployment opening surrounded at least in part by a retainer ledge recessed below the top surface. At least one separately formed door member is accommodated in the deployment opening of the retainer member and supported by the recessed retainer ledge against movement inwardly of the retainer ledge. A continuous outer flexible polymeric skin layer is spaced in overlying relation to the retainer and door members, between which an intermediate layer of foam material is foamed in place. A foam blockage seal is provided at the interface between the door member and the recessed ledge of the retainer member and is operative to block the passage of foam layer material past the door member and ledge during the formation of the foam layer.
The foam blockage seal may be formed as an integral part of the ledge and/or door or may be formed separately and applied to the ledge before installation of the door. The recessed seal eliminates the need for surface-applied masking tape and in doing so promotes complete, uniform direct adhesion of the foam layer to the underlying door and retainer members.
These and other features and advantages of the invention will become readily apparent when considered in connection with the following detailed description and drawings.